In the face of a strong challenge from the Congress-led opposition, India's governing party is preparing to unleash the charisma of Prime Minister Narendra Modi to win a second term in the general election this year.

ELECTION AT A GLANCE

Number of Lok Sabha seats: 543

COMPETING STRATEGIES

BJP-led National Democratic Alliance (NDA): Use PM Modi as its trump card and make it a presidential-style contest between him and Rahul Gandhi

- Janata Dal (United), which won only two parliamentary constituencies in Bihar in 2014, will get to contest 17 in alliance with BJP in 2019

Mr Modi, undoubtedly the most popular national leader in the country, is scheduled to address groups representing more than 120 parliamentary constituencies over the next one and a half months to prop up his party for the campaign.

This year's election, the largest in world history with 814 million eligible voters, will also be the longest. It will take place in nine phases from April 7 to May 12 with official results to be declared on May 16.

The constituencies targeted for the Modi touch by his Bharatiya Janata Party (BJP) are mostly located in northeastern and southern regions where the party is weak. It hopes to wrest some of these seats from the opposition to offset any possible setbacks in Maharashtra and Hindu heartland states including Uttar Pradesh, Madhya Pradesh, Rajasthan and Chhattisgarh.

Mr Modi set the aggressive tone for the campaign on Dec 24 at a rally in the eastern state of Odisha. He launched a blistering attack on Chief Minister Naveen Patnaik, who is seeking a fifth term in the state election that will be held concurrently with the general election.

Mr Patnaik's Biju Janata Dal (BJD) party swept the state in 2014, leaving only one of the 21 seats for the BJP. But this time he faces heavy anti-incumbency sentiment and the BJP expects to gain many seats.

The following day Mr Modi was in Assam to inaugurate the country's longest rail-road bridge over the Brahmaputra River. The bridge will connect Arunachal Pradesh to Assam, considerably reducing travel time between the two northeastern states.

The BJP hopes to win an overwhelming majority of the 25 parliamentary constituencies in the northeast, compared with just eight in 2014.

The premier's itinerary for early January includes Andhra Pradesh, Telangana, Kerala and Tamil Nadu, states in south where the BJP has never ruled on its own. In Kerala, it has never even won a parliamentary seat.

In the third week of January, Mr Modi will be in West Bengal, a state ruled by a regional party, the All India Trinamool Congress (AITC). Mamata Banerjee, the state's chief minister and head of the AITC, has been trying to cobble together a third front to challenge BJP nationally in 2019.

Though Mr Modi's popularity has diminished since 2014, he is still the most prominent mass-party leader in India. His appeal was on full display in Rajasthan where the BJP made a spectacular comeback a few days before the Dec 7 state elections and ended up winning 70 seats -- more than double the number pollsters had predicted.

A tracking poll done in September 2018 in Rajasthan, Madhya Pradesh and Chhattisgarh states showed that Mr Modi was much more popular than his party's chief ministers in those states. The popularity gap was high, ranging between 10 and 22 percentage points.

The BJP hopes the Modi blitzkrieg will disrupt some of the recent momentum shown by Congress, led by Rahul Gandhi. Mr Gandhi has made waves by promising a pan-India waiver of farm loans, but a BJP worker in New Delhi dismissed the challenge.

"Let the PM visit Madhya Pradesh, Rajasthan and Chhattisgarh and the hollowness of the Congress loan waiver will be exposed," said the party worker, who asked not to be named.

"He will ask people how many of you have benefited from the waiver, comparing it with all the welfare schemes his government has introduced, like universal health insurance and cooking gas connections for the poor, and let's see how many raise their hands."

Congress governments in the three states waived farm loans worth US$9.4 billion after wresting power from the BJP. But only farmers who had taken loans of up to 200,000 rupees ($2,845) from government banks are eligible. Those who had borrowed larger sums from state banks or taken loans from private banks or moneylenders would not qualify.

An election survey done by the media group Anand Bazar Patrika (ABP) has predicted a comfortable majority in the Lok Sabha, the 543-member lower house of Parliament, for the BJP-led National Democratic Alliance (NDA). This assumes that the Bahujan Samaj Party (BSP) and Samajwadi Party (SP), state parties in populous Uttar Pradesh, contest separately.

However, if the BSP and SP form an alliance, according to the survey, the incumbent coalition could fall 31 seats short of the 272 seats needed for a majority.

In the 2014 elections, the BJP swept Uttar Pradesh, winning 73 out of 80 seats. It also reached a saturation point in Uttar Pradesh, Madhya Pradesh, Rajasthan, Gujarat and Maharashtra, Chhattisgarh and Haryana. Few believe it can replicate those feats in 2019.

Sudheendra Kulkarni, a former BJP member turned opinion columnist, believes Mr Modi will not be able to win a majority for the party again. Last time, the BJP won 282 seats on its own.

"Mr Modi is certainly an asset to the BJP. But I am doubtful if the asset will bring the BJP back to power. It can be safely predicted that the next government will be a coalition -- either led by the BJP or Congress or someone else," Mr Kulkarni told Asia Focus.

The opposition, which has won several state elections since 2014, has a chance if it can succeed in providing a credible alternative in the next few months, he added. "The BJP got a huge mandate last time. It should reflect on why it has lost so many elections."

In any case, said Mr Kulkarni, the new government needs focus on good governance and uniting society. This was a veiled jab at the BJP, which has faced criticism for pandering to the more extreme forms of Hindu nationalism, such as the violence of "cow vigilantes" associated with its parent body Rashtriya Swayamsewak Sangh (RSS).

He also believes the party will need new allies to form a government after the polls, apart from retaining the old ones. Shiv Sena, a Hindu party that runs a coalition government with the BJP in Maharashtra, is among those that might break away.

Shiv Sena president Udhav Thackeray recently borrowed a phrase from Rahul Gandhi -- "the watchman is a thief" -- to criticise Mr Modi. Mr Gandhi has used it frequently to attack the prime minister over alleged corruption in the purchase of Rafale fighter jets from Dassault Aviation of France.

Political commentator Mohan Sahay agrees that it would be difficult for Mr Modi to return to power. He believes Mr Modi himself might decide to contest from two seats -- Gandhinagar as well as Varanasi -- in case the SP, BSP, Congress and Rashtriya Lok Dal (RLD) form an alliance in Uttar Pradesh.

Mr Sahay believes that Nitin Gadkari, a senior BJP figure who is close to RSS chief Mohan Bhagwat, is seeking to position himself as a statesman by criticising intolerance and asking Mr Modi and BJP president Amit Shah to own up to recent state electoral defeats.

In the general election, the BJP-led NDA will largely be pitted against the Congress-led United Progressive Alliance (UPA). But there are also states such as Telangana, West Bengal and Odisha that are being ruled by regional parties. These parties have been trying to stitch together a third front to make the contest more challenging.